Big brain evolution: brain size and intelligence (Evolution)

by dhw, Monday, April 16, 2018, 11:23 (925 days ago) @ David Turell

dhw: All we know is not shrinkage. We know that the modern brain responds to new concepts by complexifying and by partially expanding within the given limits of the skull (and I suggest that shrinkage is merely a by-product of efficient complexification).

DAVID: Not true. Shrinkage is a major effect of modern thought/concepts appearing as I have previously presented:

I have not denied shrinkage! I have pointed out that modern science has also shown complexification and limited expansion. I’m surprised that you ignore all the other points raised in my post concerning the “obvious” form of dualism that you outlined, whereby in dualism the soul thinks and the brain gathers information and implements the thoughts. And modern science confirms that the implementation of concepts changes the brain – the brain does not change in anticipation of new concepts. Presumably you now accept all this. Thank you.
As regards shrinkage, the article makes it clear that nobody knows why the brain has shrunk. The different theories include the following:
As the brain shrank, its wiring became more efficient, transforming us into quicker, more agile thinkers.
That is almost the same as my proposal, except that in mine it is the efficiency of the complexification process (rewiring) that reduced the need for many existing cells and connections, i.e. efficient wiring CAUSED the shrinkage. I’m surprised the author hasn’t thought of this.

dhw: My hypothesis is that early brains expanded when existing brains did not have the capacity to implement new concepts. We don’t know what concepts would have triggered expansion, but new ideas for artefacts are one possibility.
DAVID: Doesn't fit the discussion in the article.

The article does not discuss pre-sapiens expansion, or the processes whereby immaterial thought is expressed or implemented by the brain. Nor does it deny that the implementation of concepts causes complexification and limited expansion in the brain, as proven by modern science and in contrast to your claim that the brain has to expand before it can come up with new concepts. The article is only concerned with possible causes of shrinkage over the last 20,000 years (i.e. since, according to you, human thought started taking such giant strides). As shrinkage is so important to you, perhaps you should explain why you object to my explanation, and then give us your own.

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